U-clip and assembly system

ABSTRACT

A clip fastener includes a first side wall, a second side wall, and a U-shaped recess between the first side wall and second side wall. The first side wall is higher than the second side wall. The recess is at least partially defined by a surface including a first portion having relatively greater radius of curvature in the vicinity of the second side wall, a second portion having a relatively lesser radius of curvature in the vicinity of the first side wall, and an inwardly projecting ridge, said second portion and ridge at least partially defining a pocket region.

BACKGROUND

[0001] 1. Field of the Invention

[0002] The present invention relates to a U-clip and to a system for the assembly of structures, for example, furniture, and especially for furniture intended for outdoor use.

[0003] 2. Background of the Art

[0004] Various types of structures are intended to be assembled and disassembled or reconfigured (e.g., by folding or unfolding) by the user. Such structures include, for example, furniture (e.g., chairs, tables, and the like) and conveyances (carriages, strollers, and the like). Outdoor furniture, in particular, is seasonal, and should be capable of being disassembled and/or folded for storage during the off-season, inclement weather, or when simply not in use.

[0005] When assembling a structure, it is often necessary to connect a linear element, such as a crosspiece, of a frame to another linear element. The connection between the linear elements should be secure. Nevertheless, the linear elements should be easily separable by the user when intended for disassembly. What is needed is improved means for establishing a secure, but reversible connection between linear elements of a structure.

SUMMARY

[0006] A clip fastener is provided herein, the clip fastener comprising a first side wall, a second side wall, and a U-shaped recess between the first side wall and second side wall. The first side wall is higher than the second side wall. The recess is at least partially defined by a surface including a first portion having relatively greater radius of curvature in the vicinity of the second side wall, a second portion having a relatively lesser radius of curvature in the vicinity of the first side wall, and an inwardly projecting ridge, said second portion and ridge at least partially defining a pocket region.

[0007] Also provided herein is a structure including the U-clip.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various embodiments are described below with reference to the drawings wherein:

[0009]FIG. 1 is a perspective view of the U-clip of the present invention;

[0010]FIG. 2 is a side elevational view of the U-clip of the present invention;

[0011]FIG. 3 is a perspective view illustrating assembled furniture including the U-clip of the present invention;

[0012]FIG. 4 is an exploded perspective view illustrating assembly of the furniture; and,

[0013]FIGS. 5 and 6 are partly sectional side elevational views illustrating the positioning of the crossbars of the seat frame in the U-clip.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

[0014] The U-clip fastener of the present invention is adapted to permit secure and easy joining of linear members of a frame. The frame can be the frame of any type structure such as, but not limited to, furniture and conveyances such as carriages and strollers, and the like. The U-clip described herein is particularly advantageous for structures which are intended to be periodically and repeatedly assembled and disassembled or reconfigured by folding by the user. For example, outdoor furniture is often intended for seasonal use and must be periodically assembled/disassembled or reconfigured by folding. While the invention is described herein in conjunction with furniture, particularly patio or outdoor furniture, it should be remembered that such use is exemplary and should not be construed as a limitation of the invention.

[0015] Referring now to FIGS. 1 and 2, the U-clip 100 of the present invention is preferably a monolithic single piece member fabricated from a suitably strong metal, engineering plastic, or other material suitable for the purposes described herein. For example, the U-clip 100 can be fabricated from aluminum, aluminum-magnesium alloy, stainless steel, brass, or other ferrous or non-ferrous metals or alloys, polycarbonate, nylon, polyvinyl chloride (PVC), acetal, (meth)acrylate polymers, polysulfone, and the like. U-clip 100 can be fabricated by any suitable method such as casting, injection molding, extruding and/or machining the material.

[0016] U-clip 100 includes a first side wall 101 having a height H₁ and a parallel and opposite second side wall 102 having a height H₂ wherein H₁ is taller than H₂, the difference between H₁ and H₂ being distance X. The ratio of H₂/H₁ can range from 0.85 to 0.95, preferably 0.87 to 0.93, and is most preferable equal to about 0.9. The U-clip has a width W, wherein the ratio of H₁/W preferably ranges from about 1.0 to about 1.5, more preferably from about 1.2 to about 1.3. Exemplary dimensions of H₁, H₂, and W for a U-clip are given in Table I below. The length L of the U-clip is not critical and can be any suitable dimension. A typical length L can range from about 1 to 4 cm. although dimensions outside of this range are also suitable.

[0017] The U-clip 100 includes a U-shaped recess 103 between side walls 101 and 102, which is configured and dimensioned so as to receive and engage a linear member such as a crossbar of a frame, e.g., for a patio chair or other furniture. As can be seen from the view shown in FIG. 2, recess 103 is not symmetric. The side of the recess 103 in proximity to the first side wall 101 is higher than the side of the recess in proximity to the second side wall 102. Moreover, recess 103 is at least partially defined by a surface having different curvatures on its opposite sides. For example, portion 103 a of the surface of the recess in proximity to the second side wall 102 has a radius of concave curvature R₁ which is larger than the radius of concave curvature R₂ of portion 103 b of the surface of the recess in proximity to the first side wall 101. That is, portion 103 b has a relatively greater curvature than portion 103 a because its radius of curvature is smaller. Also, a lengthwise ridge 104 extends into the recess 103 on the side of the recess in proximity to the first side wall 101. An important feature of the invention is that portion 103 b and ridge 104 at least partially define a pocket at portion 103 b of the recess. For assembly of the structure, the crossbar of the frame (or other linear member) is received into the pocket and is retained therein until intentionally disengaged by the user. When, for example, furniture is being used as described below in conjunction with FIGS. 5 and 6, the normal direction of force upon the crossbar tends to bias the crossbar into the pocket 103 b. This prevents unintended disengagement of the crossbar and the U-clip.

[0018] Ridge 104 is a convexity having a radius of curvature R₃. First upper edge 108 is a convexity having a radius of curvature R₅. A concave surface portion 109 between first upper edge 108 and ridge 104 is a concavity having a radius of curvature R₄. Second upper edge 107 has a radius of curvature R₆. The radii of curvature can be selected in accordance with the desired size of the U-clip 100. Exemplary dimensions for a U-clip are set forth below in Table I. However, it is desirable to maintain certain proportions between the radii. Thus, the following ranges of ratios are preferred: Ratio Preferred More preferred R₁/R₂ 3.0-4.0 3.5-3.7 R₃/R₅ 0.9-1.0 0.92-0.95 R₅/R₆ 0.55-0.65 0.61-0.64 R₄/R₅ 7.0-8.5 7.5-8.0 R₂/W 0.20-0.25 0.22-0.24

[0019] The bottom of the U-clip 100 is fixedly fastened to the crossbeam of a support frame and optionally includes a recess 110 having a radius of curvature R₇, wherein R₇ is preferably dimensioned to fit the curvature of the crossbeam.

[0020] Optionally, U-clip 100 further includes one or more lengthwise extending parallel holes, e.g., holes 105 and 106 between the bottom of recess 103 and the bottom of the U-clip. Hole 105 has a diameter D₅ and hole 106 has a diameter D₆. Preferably, holes 105 and 106 are of the same size, i.e., D₅ is equal to D₆, wherein the ratio D₅/W (or D₆/W) preferably ranges from about 0.25 to about 0.27 and more preferably is about equal to 2.6. Holes 105 and 106 are laterally spaced apart from each other and lighten the weight of the U-clip 100 by allowing the U-clip 100 to be made with less material. However, holes 105 and 106 are configured, dimensioned and positioned such that the strength of the U-clip 100 is not significantly reduced by having holes 105 and 106.

[0021] Table I below sets forth exemplary relative dimensions for a U-clip. The units given can be any units (millimeters, centimeters, inches, etc.) and the dimensions can be proportionately scaled upward or downward as required. For use in conjunction with a typical patio chair such as illustrated in FIGS. 3 and 4 herein, the units given in Table I can be taken as millimeters. TABLE I Dimension Units H₁ 31.0 H₂ 28.0 W 25.0 R₁ 20.75 R₂ 5.75 R₃ 1.36 R₄ 11.5 R₅ 1.46 R₆ 2.34 R₇ 12.0 D₅, D₆ 6.5

[0022] Referring now to FIGS. 3 and 4, a patio chair 10 is illustrated wherein patio chair 10 includes a seat member 30 and a support frame 20. Seat member 30 includes a seat frame 31 and a body support 34 including a back portion 35 and seat portion 36. Seat frame 31 includes an upper crossbar 32 and a lower crossbar 33 extending laterally between side portions 37. Support frame 20 includes arm rest side portions 21, base 24, and upper rear crossbeam 22 and lower front crossbeam 23 extending laterally between side portions 21.

[0023] Two U-clips 100 are fixedly secured to each of the upper and lower lateral crossbeams 22 and 23 by any suitable method such as adhesive bonding, soldering, welding, use of fastening members (e.g., screws, bolts, etc.). Preferably, the U-clips 100 are secured to the respective crossbeams 22, 23 by welding.

[0024] The chair 10 is assembled by positioning the seat member 30 and support frame 20 such that the upper crossbar 32 engages the U-clips 100 attached to the upper crossbeam 22, and the lower crossbar 33 engages the U-clips 100 attached to the lower crossbeam 23.

[0025] Referring also now to FIGS. 5 and 6, it can be appreciated that when a weight is applied to the seat member 30 by a person occupying chair 10, downwardly directed force F is applied to the crossbars 32 and 33. The U-clips are positioned such that the pockets 103 b are oriented towards a vertical plane extending laterally through the center of gravity of the chair. That is, the pockets of the U-clips 100 attached to the upper rear crossbeam 22 are oriented forward, and the pockets of U-clips 100 attached to the lower front crossbeam 23 are oriented rearward. Accordingly, a force F acting upon the crossbars 32 and 33 when the chair is occupied will bias the crossbars 32 and 33 into the pockets in which they are seated. Ridges 104 help retain the crossbars 32 and 33 in their respective pockets and prevent unintended disengagement from the U-clips. Also the support frame 20 preferably has resiliency sufficient to permit bending of the support frame 20 to facilitate engagement of the seat member with the U-clips 100. Thus, the engagement of crossbars 32 and 33 with the U-clips 100 can be a snap-fit type of engagement, wherein the biasing force of the support frame 20 is also oriented so as to maintain the crossbars 32 and 33 in their respective U-clip pockets.

[0026] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possibilities within the scope and spirit of the invention as defined by the claims appended hereto. 

What is claimed is:
 1. A clip fastener comprising: a first side wall, a second side wall, and a U-shaped recess between the first side wall and second side wall, wherein the first side wall is higher than the second side wall, and wherein the recess is at least partially defined by a surface including a first portion having relatively greater radius of curvature in the vicinity of the second side wall, a second portion having a relatively lesser radius of curvature in the vicinity of the first side wall, and an inwardly projecting ridge, said second portion and ridge at least partially defining a pocket region.
 2. The clip fastener of claim 1 wherein the clip fastener is a monolithic, single piece member fabricated from a material selected from the group consisting of aluminum, aluminum-magnesium alloy, stainless steel, brass, polycarbonate nylon, polyvinyl chloride, acetal, (meth)acrylate polymer and polysulfone.
 3. The clip fastener of claim 1 wherein the first side wall and second side wall are substantially parallel to each other and on opposite sides of the clip fastener.
 4. The clip fastener of claim 3 wherein the first side wall has a height H₁ and the second side wall has a height H₂ and the ratio H₁/H₂ ranges from about 0.85 to 0.95.
 5. The clip fastener of claim 1 wherein the first portion of the recess surface has a radius of curvature R₁ and the second portion of the recess surface has a radius of curvature R₂ wherein the ratio R₁/R₂ ranges from about 3.0 to about 4.0.
 6. The clip fastener of claim 1 wherein the clip fastener has a width W, and the clip fastener further includes at least a lengthwise extending first hole having a diameter D wherein the ratio of D/W ranges from about 0.25 to about 0.27.
 7. The clip fastener of claim 6 further including a second hole parallel to the first hole and having the same diameter as the first hole, said second hole being laterally spaced apart from the first hole.
 8. The clip fastener of claim 1 further including a bottom surface having a lengthwise extending concavity.
 9. The clip fastener of claim 1 wherein the first side wall has a height H₁ and the clip fastener has a width W, wherein the ratio of H₁/W ranges from about 1.2 to about 1.3.
 10. A structure comprising: a) at least one frame and at least first and second linear members; b) at least one U-clip fastener fixedly attached to the first linear member, the U-clip fastener being configured and dimensioned so as to engage the second linear member, said U-clip fastener including, a first side wall, a second side wall, and a U-shaped recess between the first side wall and second side wall, wherein the first side wall is higher than the second side wall, and wherein the recess is at least partially defined by a surface including a first portion having relatively greater radius of curvature in the vicinity of the second side wall, a second portion having a relatively lesser radius of curvature in the vicinity of the first side wall, and an inwardly projecting ridge, said second portion and ridge at least partially defining a pocket region for receiving the second linear member.
 11. The structure of claim 10 wherein said structure comprises a chair.
 12. The structure of claim 11 wherein the chair has a support frame and a seat member, the seat member including a seat frame and a body support, wherein the support frame includes at least first and second lateral support frame crosspieces and the seat frame includes at least first and second seat frame crosspieces, each of the first and second support frame crosspieces having attached thereto at least one said U-clip fastener for engaging a respective seat frame crosspiece.
 13. The structure of claim 10 wherein the U-clip fastener is a monolithic, single piece member fabricated from a material selected from the group consisting of aluminum, aluminum-magnesium alloy, stainless steel, brass, polycarbonate nylon, polyvinyl chloride, acetal, (meth)acrylate polymer and polysulfone.
 14. The structure of claim 10 wherein the first side wall and second side wall of the U-clip fastener are substantially parallel to each other and on opposite sides of the clip fastener.
 15. The structure of claim 14 wherein the first side wall has a height H₁ and the second side wall has a height H₂ and the ratio H₁/H₂ ranges from about 0.85 to 0.95.
 16. The structure of claim 10 wherein the first portion of the recess surface of the U-clip fastener has a radius of curvature R₁ and the second portion of the recess surface has a radius of curvature R₂ wherein the ratio R₁/R₂ ranges from about 3.0 to about 4.0.
 17. The structure of claim 10 wherein the U-clip fastener has a width W, and the U-clip fastener further includes at least a lengthwise extending first hole having a diameter D wherein the ratio of D/W ranges from about 0.25 to about 0.27.
 18. The structure of claim 17 wherein the U-clip fastener further includes a second hole parallel to the first hole and having the same diameter as the first hole, said second hole being laterally spaced apart from the first hole.
 19. The structure of claim 10 wherein the U-clip fastener further includes a bottom surface having a lengthwise extending concavity dimensioned and configured to engage the first linear member.
 20. The structure of claim 10 wherein the first side wall of the U-clip fastener has a height H₁ and the U-clip fastener has a width W, wherein the ratio of H₁/W ranges from about 1.2 to about 1.3. 